ZapPulse 2.3SE

ZapPulse 2.3SE are mono modules based on PWM (class-D) amplifier technology. This tiny module can produce up to 290 Watts of pure Audio
Power in 8 Ohms, 580 Watts in 4 Ohms and 1000 Watts in 2 Ohms RMS Continuous power.
The module size is exactly the same as a normal credit card!
Since the efficiency is extremely high (some 96%), almost no heat sinking is required.

Power Loss curve showing the losses in a PWM amplifier, at different power levels, compared to that of a
normal Class A/B amplifier. As can be seen, at most listening levels of this 100W amplifier depicted in
the curve, about 60 Watts of power is dissipated in the heat sink. Even at lower powers like 30W. This
draws a lot of valuable power from the power supply. In a ZapPulse based amplifier almost no such loss
should be encountered, and so you are not required to oversize the power supply, like would be normal
when using a traditional class A/B amplifier. In fact you can mostly get away with under-sizing the power
supply, because the music does not have 100% thermal power content. Measurements of practical music
examples show that most types of music contain an average 30% thermal power measured over 30 minutes. In
other words you can make a 300 Watts RMS amplifier with just a 100 VA mains transformer, if the amplifier
is based on ZapPulse. This is a limit, and even if it will work in practical installations, we do not
recommend this dimensioning. In practical amplifiers we recommend a 1:1 ratio of transformer size to
output power. So a 2x200 W amplifier should use a transformer of 400 VA or more.

The ZapPulse module has a footprint equal to a normal credit card. To operate, the module must be
connected with plus and minus 60V DC, GND, input signal, and speaker load. In other words the hook-up is
extremely simple.

Furthermore you can connect an external gate driver voltage (recommended) to reduce the idle loss from 12
to 6 Watts per module. This should keep your amplifier so cool that you can't feel if it's on or off on
top of the enclosure! Even at full power load...There is also a remote shutdown feature, which can be
used to set the module in standby mode, with a 0 - 5 V signal (0 V = standby), or using a relay or
switch. Many modules can be connected directly together for simultaneous shutdown.

On this photo we show how the ZapPulse modules are connected to the companion Predator power supply
board. This board has all the functions you need including the external gate drive supply. There are no
backsides to using the external gate driver, but also no sonic gains, so it is only a short way to
squeezing the last bit of saved power out of your high performance power amplifier. So why not use it?
The external gate driver supply is driven by a separate transformer winding of 15 V AC, why we recommend
your transformer to have a such. A separate transformer of 15 VA or more can also be used for this
purpose.

A rugged varistor prevents the development of high voltage spikes in case the load is removed from the
amplifier in high power operation. This way the ZapPulse 2.3SE module is completely safe at load dumping
situations.

The ZapPulse module is cooled by mounting it on a metal plate in the bottom of the enclosure, either
amplifier or active loudspeaker. Even a steel sheet plate of 1 mm gives sufficient cooling for 200 Watts
RMS power! Of course aluminium is better as a heat conductor, but also it is non magnetic, which is as
always beneficial for sound quality. We recommend an aluminium sheet plate of 2 mm thickness or more, size
A5 (half letter) or more per module at full power. There is no reason to use a 'real' heat sink. The
primary power loss is idling loss, which is some 12 Watts per module in a 200 Watts setup. At full power
the total dissipation is 18 - 20 Watts per module. To reduce the idle loss you can use the external gate
drive option. This allows you to inject a gate driver voltage of 18-20V DC and thus reduce power loss by
5-6 Watts. Effectively halving the idle loss. This is done simply by adding a 4th wire to the predator
power supply (shown below), and removing a solder bubble from the module. See cookbook.

To make mounting extremely easy and always safe, the power parts are mounted on an isolated aluminium
block, that only need to be fastened on the sheet metal plate. Screws are included and no compound is
required.

To build a complete 2 x 200 Watts Power Amplifier, you need the following parts: